Z' search in e(+)e(-) annihilation

Expectations for constraints on extra Z bosons are derived for LEP 2 and future linear e(+)e(-) colliders. For typical GUTs, a Z' with M-Z' less than or equal to 3 to 6 root s may cause observable effects. The Z' discovery limits are dominated by statistical errors. However, if a Z' signal is observed, the discrimination between different models becomes much worse if systematic errors are taken into account. Discrimination between models is possible for M-Z' < 3 root s. A determination of Z'f (f) over bar couplings independently of models becomes attractive with future colliders. Anticipated bounds are determined.